A robust literature has investigated homicide trends in the United States since 1950. The prevalence of homicide in the country almost doubled in the 1960s, remained high until the 1990s and then declined precipitously. Surprisingly, Canada displayed the same trend. We decompose the age, period and cohort effects on the homicide trends of the United States and Canada since 1950, exploring shared effects in light of these countries’ historical and policy differences over the past seven decades. Our study reveals remarkably similar trends and effects in Canada as those previously documented for the United States, despite diverging approaches to criminal justice and to the use of incarceration since the 1950s. We explore these findings and expand on their implications.

中文翻译：

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加拿大和美国的凶杀趋势之间的年龄，时期和同类人群差异

自1950年以来，有大量文献调查了美国的凶杀趋势。在1960年代，该国的凶杀发生率几乎翻了一番，直到1990年代一直很高，然后急剧下降。令人惊讶的是，加拿大显示出相同的趋势。自1950年以来，我们分解了年龄，时期和同类人群对美国和加拿大凶杀趋势的影响，并根据这些国家过去七十年的历史和政策差异，探讨了共同的影响。我们的研究表明，尽管自1950年代以来，在刑事司法和使用监禁方法上存在分歧，但加拿大的趋势和影响却与以前在美国记录的趋势和影响极为相似。我们探索这些发现并扩展其含义。